CVE-2026-35568: CWE-346: Origin Validation Error in modelcontextprotocol java-sdk
MCP Java SDK is the official Java SDK for Model Context Protocol servers and clients. Prior to 1.0.0, the java-sdk contains a DNS rebinding vulnerability. This vulnerability allows an attacker to access a locally or network-private java-sdk MCP server via a victims browser that is either local, or network adjacent. This allows an attacker to make any tool call to the server as if they were a locally running MCP connected AI agent. This vulnerability is fixed in 1.0.0.
AI Analysis
Technical Summary
The MCP Java SDK before version 1.0.0 contains a DNS rebinding vulnerability classified as CWE-346 (Origin Validation Error). This flaw allows an attacker to bypass origin checks by manipulating DNS responses, thereby gaining unauthorized access to local or network-private MCP servers through a victim's browser. Exploitation permits the attacker to perform any tool call on the MCP server with the privileges of a local MCP-connected AI agent. The vulnerability has a CVSS 4.0 base score of 7.6, indicating high severity. The issue is resolved in MCP Java SDK version 1.0.0.
Potential Impact
Successful exploitation allows an attacker to remotely invoke any tool call on the MCP Java SDK server as if they were a local AI agent, potentially leading to unauthorized actions within the MCP environment. This could compromise the integrity and functionality of the MCP server and its connected AI agents. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade the MCP Java SDK to version 1.0.0 or later, where this DNS rebinding vulnerability is fixed. Since the vulnerability is resolved in the updated version, applying this official fix is the recommended remediation. Patch status is confirmed by the vendor stating the issue is fixed in 1.0.0. No additional mitigations are indicated.
CVE-2026-35568: CWE-346: Origin Validation Error in modelcontextprotocol java-sdk
Description
MCP Java SDK is the official Java SDK for Model Context Protocol servers and clients. Prior to 1.0.0, the java-sdk contains a DNS rebinding vulnerability. This vulnerability allows an attacker to access a locally or network-private java-sdk MCP server via a victims browser that is either local, or network adjacent. This allows an attacker to make any tool call to the server as if they were a locally running MCP connected AI agent. This vulnerability is fixed in 1.0.0.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The MCP Java SDK before version 1.0.0 contains a DNS rebinding vulnerability classified as CWE-346 (Origin Validation Error). This flaw allows an attacker to bypass origin checks by manipulating DNS responses, thereby gaining unauthorized access to local or network-private MCP servers through a victim's browser. Exploitation permits the attacker to perform any tool call on the MCP server with the privileges of a local MCP-connected AI agent. The vulnerability has a CVSS 4.0 base score of 7.6, indicating high severity. The issue is resolved in MCP Java SDK version 1.0.0.
Potential Impact
Successful exploitation allows an attacker to remotely invoke any tool call on the MCP Java SDK server as if they were a local AI agent, potentially leading to unauthorized actions within the MCP environment. This could compromise the integrity and functionality of the MCP server and its connected AI agents. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade the MCP Java SDK to version 1.0.0 or later, where this DNS rebinding vulnerability is fixed. Since the vulnerability is resolved in the updated version, applying this official fix is the recommended remediation. Patch status is confirmed by the vendor stating the issue is fixed in 1.0.0. No additional mitigations are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-03T20:09:02.826Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d5779eaaed68159a6ad786
Added to database: 4/7/2026, 9:31:10 PM
Last enriched: 4/7/2026, 9:46:07 PM
Last updated: 4/8/2026, 12:42:36 AM
Views: 17
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